Cant install my pinnacl 110i on windows 7. ...

Download updated VISTA drivers from here: http://cdn.pinnaclesys.com/SupportFiles/PCTV%20Drivers/ReadmePCTV.htm
If the driver have an installer try to install from it.
If not success try to run the installer in compatibility mode (right click - properties - compatibility tab - run in compatibility mode with WINDOWS VISTA)
If all of those steps faill try to MANUALLY install the driver:
Go to device manager, select your device, right click on it and select update controller software - try to find it in Windows Update (online)
If not driver available online try again, but select the "find on my computer" option, and select a folder containing the drivers.
An excellent website to find drivers and solutions is: http://www.driverguide.com